Qt for Embedded Linux Virtual Framebuffer+
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The virtual frame buffer allows a Qt for Embedded Linux program to be developed+
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on your desktop machine, without switching between consoles and X11.  The virtual+
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framebuffer consists of a shared memory region (the virtual frame buffer)+
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and a utility to display the framebuffer in a window.  The display is updated+
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periodically, so you will see discrete snapshots of the framebuffer rather+
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than each individual drawing operation.  For this reason drawing problems+
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such as flickering may not be apparent until the program is run using a real+
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framebuffer.+
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To use the virtual framebuffer:+
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+
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1. Ensure QT_NO_QWS_VFB is not set in qconfig.h (when you configure Qt,+
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    add the -qvfb option).+
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2. Start qvfb (qvfb should be compiled as a normal Qt for X11 application,+
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    NOT as a Qt for Embedded Linux application!).+
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3. Start a Qt for Embedded Linux server (i.e. construct QApplication with+
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   QApplication::GuiServer flag, or run a client with the -qws option).+
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qvfb supports the following command line options:+
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+
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[-width width]   the width of the virtual framebuffer (default: 240).+
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[-height height] the height of the virtual framebuffer (default: 320).+
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[-depth depth]   the depth of the virtual framebuffer (1,4,8 or 32, default: 8).+
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[-nocursor]      do not display the X11 cursor in the framebuffer window.+
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[-qwsdisplay]    the Qt for Embedded Linux display ID, e.g. -qwsdisplay :1 (default :0).+
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[-skin skinfile] tells qvfb to load a skin file, e.g. -skin pda.skin+
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Please refer to the file "pda.skin" as an example of what a skin file looks like.+
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The format for skin files is:+
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    Image filename of skin with buttons in their up positions+
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    Image filename of skin with buttons in their down positions+
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    X offset of top left corner of the virtual screen on the skin image+
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    Y offset of top left corner of the virtual screen on the skin image+
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    Width of the virtual screen on the skin image+
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    Height of the virtual screen on the skin image+
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    Number of defined button regions+
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Then for each button region the format is:+
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    Button identifier+
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    Qt scan codes to generate for the button+
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    Top left X coordinate of the button region+
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    Top left Y coordinate of the button region+
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    Bottom right X coordinate of the button region+
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    Bottom right Y coordinate of the button region+
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The virtual framebuffer is a development tool only.  No security issues have+
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been considered in the virtual framebuffer design.  It should not be used+
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in a production environment and QT_NO_QWS_VFB should always be in force+
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in production libraries.+
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